Impact switch with inertia operated toggle linkage actuator mechanism

ABSTRACT

An impact-responsive, inertia-actuated switch includes a pair of arms at least one of which is pivoted at its end for swinging movement toward and away from the other arm and a toggle linkage connected between the arms. Upon impact or high deceleration an inertia member connected to the toggle linkage causes the latter to move over-center against a spring bias, and the resulting movement of the pivoted arm engages or disengages a pair of electrical contact members carried by the arms. The switch has special utility as the actuator in an automatic crash signal device for aircraft.

United States Patent Baland Sept. 17, 1974 3,728,508 4/1973 Netzel 200/153 V Primary Examiner-James R. Scott Attorney, Agent, or Firm-Cushman, Darby &

[76] Inventor: Raymond W. Baland, 2208 Milam, Cushman Amarillo, Tex. 79109 [22] Filed: Apr. 13, 1973 ABSTRACT An impact-responsive, inertia-actuated switch includes [21] Appl' 350989 a pair of arms at least one of which is pivoted at its end for swinging movement toward and away from the [52] US. CL... ZOO/61.45 R, ZOO/61.53, 200/ 153 G, other arm and a toggle linkage connected between the 200/ 153 H arms. Upon impact or high deceleration an inertia [51] Int. Cl ..H01h 35/02, l-IOlh 3/46 member connected to the toggle linkage causes the [58] Field of Search 200/52 R, 61.08, 61.44, latter to move over-center against a spring bias, and ZOO/61.45 R, 61.52, 61.53, 153 G, 153 V, the resulting movement of the pivoted arm engages or 153 SC, 153 H; 102/73 R; 340/61 disengages a pair of electrical contact members carried by the arms. The switch has special utility as the [56] References Cited actuator in an automatic crash signal device for air- UNITED STATES PATENTS craft 3,349,208 10/1967 Cataldo et a1. 200/153 G 5 Claims, 3 Drawing Figures 44 50 68 e 4g K 8 73 /6 I m E /4- ,25'

27 5 4 Z3 77 Q/ I l/ i i /29 33 i 20 IMPACT SWITCH WITH INERTIAOPERATED TOGGLE LINKAGE ACTUATOR MECHANISM BACKGROUND OF THE INVENTION AND BRIEF DESCRIPTION OF THE PRIOR ART Severalprior artdevices have been developed for'insuring that a transmitting device emits signals after an airplane has crashed, for the purpose of indicating the location of the aircraft.

One such device is illustrated in the 'U.S. Pat. to Camp, No. 2,473,050,-wherein there is disclosed asig- -nalling device thatisthrown outwardly from a crashed plane. A disadvantage that can occur with the use of this deviceis that,it can bedamaged during either the throw-off processor the crash of theplane.

Anotherknown type of impact switch is that illustrated in .the US. Pat. of Fey, No. 3,335,239, wherein an impact switch is housed within a flexible :plastic shell. However, due to the :flexible walls, this type of switch might not-provide sufficient strength and rug- .gedness during ahigh-impact.

A still *further prior art impact responsive switch :is illustrated in the US. Patent to Gallistel et al., 3,226,504. However, the switch inthispatent is-complicated;indesign and construction and thusly expen sive to manufacture.

SUMMARY'OF THE INVENTION The presentginvention provides an improved inertia responsive switch that is inexpensive in manufacture, durable in construction,-and efficient in operation. The inertia responsive switch comprises a linkage system made of relatively strongtmaterial switch terminals operatively arranged with thellinkage-system and effective tomove between open and closed positions, and an inertia member operatively connectedto the linkage sys- "tem so as to effectuate an opening or'closing of the switchterminals when the inertia responsive-member moves relative to the linkage system upon .impactor high deceleration of the switch. In the preferred eminvention will become apparent from'the following detailed descriptionof the invention when considered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION :OF THE DRAWINGS FIG. 1 is a side elevational view of the inertiaresponsive switchmadein accordance with the principles of the invention and showingthe switch in its inoperative position prior .to impact; FIG.'2 is a fragmentary view, on an enlarged scale, of

partof FIG. 1; and

FIG. 3 is another view of the inertia-responsive switch, but shown in a'position wherein the switch is closed after impact of a vehiclecarrying th switch.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring .to the drawings, there -is illustrated a pretive purposes only, the switch to be described is used in combination with a conventional distress signal transmitter.

As seen in-FIG. 1, the impact-responsive switch is shown in an open position with the terminals 14 and 16 not contacting each other. The linkage system disclosedis preferably constructed from high-strength material (e.g., steel). Therefore, the linkage system is capable of withstanding the high loads that are exerted during a crash of the airplane and acting as a ground for the switch.

The switch arms 20 and 22 are supported in any suitable manner which permits at least one of them to swing relative to the other. As shown, one end of the arm 22 is pivotally connected at 23 to a foot portion 25 which is integral with or fixed to thecorresponding end of the arm 20.

The toggle linkage system 24 includes first and second pairs of toggle links, the first pair of links .26, 27

:second pairs of toggle links-by a rod 44. The rod 44 is attached to the toggle system 24 at the location of the pins '28 and 30. The inertia element 28 may be comprised of a plurality of plates 46, each of which is mounted on a threaded end portion of the rod 44 and held in position by a nut 48. The numberof plates 46 can be selectively varied'so as to adjust the massof the element 18, thereby permitting a change in parameters of the inertia switch 10.

As viewed in FIGS. 1 and 3, an arcuate stop member 50 is securely attachedby, for example, rivets 51 to the intermediate portion of the link 30. In this particular embodiment, the stop is shown in a generallyarcuate configuration; however, it is to be understood that otherconstructions are conceivable within the scope of the invention. The stop has a generally flat forward end 52 and a generally flat intermediate surface 54. The forward surface is effective to contactan intermediate portion of the link.3l when the system is in its cooked or open position as showmin FIG. 1. The intermediate surface 54 is effective to contact the arm 20 when the system is in its actuated or closed position as shown in FIG. 3.

,In the open position of the switch 10 the engagement of the stopsurface 52 with the link 31 limits the movement of the arm 22 toward the arm 20 therebypreventing engagement of the contacts 14 and 16. In the closed position of the switch the engagement of the stop surface 54 with the arm 22 limits the ,movementof that arm toward-the arm 20 so as to preventdestruction of the contacts 14 and 16 by crushing.

The springs 58, 60 normally maintain the inertia ele- I ment 18 in the preimpact position as shown in FIG. 1. The turnbuckle 62 can be manipulated to vary the force of the springs so as to determine the magnitude of deceleration required to commence the longitudinal movement of the inertia element 18 in response to a crash. This is a safety feature which permits a control of the switch so that it will not be actuated when an airplane lands or an automotive vehicle suddenly brakes.

The contact 16 is constructed as a plunger slidably received within a bore 70 in a link 71 which is pivotally connected to the switch arm 22 at 72. A spiral spring 73 surrounds the shank of the contact 16 and is secured at one end to the head of the contact 16 and at its other end to the end of the link 71. The shank is electrically insulated from the link 71 by a sleeve 74 and can be connected into an electric circuit for a distress signal transmitter by means of a wire 75. The contact 14 is similarly mounted by a spring-76 in a bore in a fixed projection 77 on the arm 20 except that the contact shank is in electrical contact with the projection 77. The arm 20 may be connected into the electrical circuit, as indicated by the ground symbol. To ensure that the contacts 14 and 16 align properly in the closedposition of the switch a link 78 is pivotally connected at one end at 79 to the link 71 and at its other end to the foot portion 25 at 80.

The switch 10' operates in the following manner. The stationary switch arm 20 is appropriately secured to the airplane by any suitable means (not shown). The inertia element 18 and the connecting rod 44 are moved rightwardly so that the toggle linkage system 24 also moves rightwardly. This movement continues until the forward face 52 of the stop member 50 contacts the toggle link 31. The springs 58 and 60 hold the parts in' this position, as shown in FIG. 1.

If there is a crash of the aircraft, the inertia force of the inertia element 18 is transmitted by the rod 44 to the toggle system and causes both pairs of toggle links to pass over-center against the force of the springs 58, 60 to their FIG. 2 position in which the stop surface 54 engages the arm 22. Simultaneously the arm 22 moves first away from and then toward the arm 20 to effect engagement of the contact 16 with the contact 14. The springs 73 and 76 permit the contacts to adjust within their bores so that the contacts are not damaged.

It will be understood that various changes may be made. in the form, details, arrangement and proportion of the parts without departing from the scope of the invention. For example, the switch 10 can be disposed so that the toggle system 24 operates in the reversedirection from that showmand the contacts 14 and 16' can be arranged to cooperate in various ways with the arms 20 and 22.

What is claimed as'novel and unobvious and desired to be protected by Letters Patent is set forth in the appended claims.

What is claimed is:

1. An inertia actuatedswitch assembly for use in connection with an electrical circuit that is to be selectively operated thereby comp'ri'sin'gatwo longitudinally extending arms; pivot means atone end of at least one of the arms mounted said one arm for swinging movement toward and away from the other arm in the plane of the arms; atoggle linkage pivotallyconnected between said arms so as to be pivoted between first andsecond positions on opposite sides of dead center; inertia means carried by said toggle linkage for moving saidlinkag'er;

from its first position to its'second posit iii response to a predetermined deceleration force whereupon said 5 one arm swings away from the other arm from a first position and then swings toward the other arm to a second position;-bias means biasing said one arm and said toggle linkage in one of their positions, said bias means including two tension springs each having one end attached to one of said arms and means interconnected to the other ends of the springs for adjusting the tension of the springs; switch means operated by movement of i said arms and toggle linkage between their positions for engaging or disengaging a pair of electrical contacts during such movement, and stop means for stopping the movement of said arms and toggle linkage in their second positions.

2. An inertia actuated switch assembly for use in connection with an electrical circuit that is to be selectively operated thereby comprising: two longitudinally extending arms; pivotmeans at end of at least one of the arms mounting said one arm for swinging movement toward and away from the other arm in the plane of the arms; a toggle linkage pivotally connected between said arms so-as to be pivotal between first and second positions on opposite sides of dead center; inertia means carried by said toggle linkage for moving siad linkage from its first position to its second position in response to a predetermined deceleration force whereupon said one arm swings away from the other arm from a first position and then swings toward the other arm to a second position; bias means biasing said one arm and said toggle linkage in one of their positions; switch means operated by movement of said arms and toggle linkage between their positions for engaging or disengaging a pair of electricalcontacts during such movement; and

stop means for stopping the movement of said arms and toggle linkage in their first and second positions, said stop means including an arcuate member carried by said toggle linkage for alternate engagement with said toggle linkage and one of said arms.

3. An inertia actuated switch assembly for use in con nection with an electrical circuit that is to be selectively operated thereby comprising: two generally parallel arms; pivot means at one end of at least one of the arms mounting said one arm for swinging movement toward and away from the other arm in the plane of the arms; a toggle linkage pivotallyconnected between said arms so as to be pivotal'between first and second positions on opposite sides of dead center; inertia means carried by movement of said arms and toggle linkage between their positions for engaging or disengaging a pair of electrical contacts during such movement; and stop means carried by said toggle linkage for stopping the movement of said arms and toggle linkage in their first and second positions.

4. An inertia actuated switch comprising: an arm and toggle assembly including first and second anns pivoted together at their inner ends so that one arm may swing toward and away from the other arm in the plane of the arms and further including two toggle linkages disposed between the arms and pivotally connected to the arms at longitudinally spaced apart locations on the arm so as to be pivotal between first and second positions on opposite sides of dead center; inertia means for moving said linkage from one position to the other in response to a predetermined deceleration force, said inertia means including a rod connected to both toggle linkages and having a free end adjacent the outer ends of the arms and a weight carried on said free end; bias means biasing said arms and toggle linkages in one of their positions; and two switch elements carried by said arm and toggle assembly in positions such that they are in engagement in one position of the arms and toggle linkages and are out of engagement in the other position of the arms and toggle linkages.

5. An inertia actuated switch assembly for use in connection with an electrical circuit that is to be selectively operated thereby comprising: two longitudinally extending arms; pivot means at one end of at least one of the arms mounting said one arm for swinging movement toward and away from the other arm in the plane of the arms; a toggle linkage pivotally connected be tween said arms so as to be pivotal between first and second positions on opposite sides of dead center; inertia means carried by said toggle linkage for moving said linkage from its first position to its second position in response to a predetermined deceleration force whereupon said one arm swings away from the other arm from a first position and then swings toward the other arm to a second position; bias means biasing said one arm and said toggle linkage in one of their positions; an electrical contact carried by said of said arms and arranged such that they engage each other when said arms are in one of their positions and are out of engagement when said arms are in their other position. 

1. An inertia actuated switch assembly for use in connection with an electrical circuit that is to be selectively operated thereby comprising: two longitudinally extending arms; pivot means at one end of at least one of the arms mounted said one arm for swinging movement toward and away from the other arm in the plane of the arms; a toggle linkage pivotally connected between said arms so as to be pivoted between first and second positions on opposite sides of dead center; inertia means carried by said toggle linkage for moving said linkage from its first position to its second position in response to a predetermined deceleration force whereupon said one arm swings away from the other arm from a first position and then swings toward the other arm to a second position; bias means biasing said one arm and said toggle linkage in one of their positions, said bias means including two tension springs each having one end attached to one of said arms and means interconnEcted to the other ends of the springs for adjusting the tension of the springs; switch means operated by movement of said arms and toggle linkage between their positions for engaging or disengaging a pair of electrical contacts during such movement, and stop means for stopping the movement of said arms and toggle linkage in their second positions.
 2. An inertia actuated switch assembly for use in connection with an electrical circuit that is to be selectively operated thereby comprising: two longitudinally extending arms; pivot means at end of at least one of the arms mounting said one arm for swinging movement toward and away from the other arm in the plane of the arms; a toggle linkage pivotally connected between said arms so as to be pivotal between first and second positions on opposite sides of dead center; inertia means carried by said toggle linkage for moving siad linkage from its first position to its second position in response to a predetermined deceleration force whereupon said one arm swings away from the other arm from a first position and then swings toward the other arm to a second position; bias means biasing said one arm and said toggle linkage in one of their positions; switch means operated by movement of said arms and toggle linkage between their positions for engaging or disengaging a pair of electrical contacts during such movement; and stop means for stopping the movement of said arms and toggle linkage in their first and second positions, said stop means including an arcuate member carried by said toggle linkage for alternate engagement with said toggle linkage and one of said arms.
 3. An inertia actuated switch assembly for use in connection with an electrical circuit that is to be selectively operated thereby comprising: two generally parallel arms; pivot means at one end of at least one of the arms mounting said one arm for swinging movement toward and away from the other arm in the plane of the arms; a toggle linkage pivotally connected between said arms so as to be pivotal between first and second positions on opposite sides of dead center; inertia means carried by said toggle linkage for moving said linkage from its first position to its second position in response to predetermined deceleration force whereupon said one arm swings away from the other arm from a first position and then swings toward the other arm to a second position; bias means restraining said one arm and said toggle linkage against movement away from whichever position these elements occupy; switch means operated by movement of said arms and toggle linkage between their positions for engaging or disengaging a pair of electrical contacts during such movement; and stop means carried by said toggle linkage for stopping the movement of said arms and toggle linkage in their first and second positions.
 4. An inertia actuated switch comprising: an arm and toggle assembly including first and second arms pivoted together at their inner ends so that one arm may swing toward and away from the other arm in the plane of the arms and further including two toggle linkages disposed between the arms and pivotally connected to the arms at longitudinally spaced apart locations on the arm so as to be pivotal between first and second positions on opposite sides of dead center; inertia means for moving said linkage from one position to the other in response to a predetermined deceleration force, said inertia means including a rod connected to both toggle linkages and having a free end adjacent the outer ends of the arms and a weight carried on said free end; bias means biasing said arms and toggle linkages in one of their positions; and two switch elements carried by said arm and toggle assembly in positions such that they are in engagement in one position of the arms and toggle linkages and are out of engagement in the other position of the arms and toggle linkages.
 5. An inertia actuated switch assembly for use in connection with an electrical circuit that is to be selectively operated therEby comprising: two longitudinally extending arms; pivot means at one end of at least one of the arms mounting said one arm for swinging movement toward and away from the other arm in the plane of the arms; a toggle linkage pivotally connected between said arms so as to be pivotal between first and second positions on opposite sides of dead center; inertia means carried by said toggle linkage for moving said linkage from its first position to its second position in response to a predetermined deceleration force whereupon said one arm swings away from the other arm from a first position and then swings toward the other arm to a second position; bias means biasing said one arm and said toggle linkage in one of their positions; an electrical contact carried by said of said arms and arranged such that they engage each other when said arms are in one of their positions and are out of engagement when said arms are in their other position. 